rtw89: fix misconfiguration on hw_scan channel time

Without this patch, hw scan won't stay long enough on DFS/passive
channels. Found previous logic error and fix it.

Signed-off-by: Po Hao Huang <phhuang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220401055043.12512-5-pkshih@realtek.com